This invention relates to sound-activated devices, and more particularly, to devices which employ a motor to impart a rotary movement to some object.
Sound-activated devices of various types are known, and such devices can: (1) issue an alarm in the event of an intrusion; (2) illuminate a room upon detection of sound which exceeds a predetermined level; (3) control the direction of movement of a toy automobile; or (4) control the operation of other devices.
Such devices and sound-activated circuits are disclosed in the following U.S. Pat. Nos.: 3,119,201; 3,270,216; 3,748,496; 3,761,912; 3,898,383, 4,024,413; 4,027,425; 4,086,724; and 4,099,168.
However, it has been determined that it is desirable to have a sound-activated device which includes a motor for imparting rotary movement to an object for a predetermined length of time. Such devices can include a turntable having figures thereon; a circular display which moves past a window; a hanging unit from which a mobile or like devices can be suspended; or a fan which blows air across an air freshener.
Devices such as a hanging mobile are desirable for entertaining an infant. For example in the event the infant cries, such cries would activate the mobile for a predetermined length of time so as to entertain the child. If at the end of that length of time the child stops crying, then the device would not be reactivated. However, if the infant still cried, then the device could be reactivated to further entertain the child. Other such uses are contemplated.
It is therefore an object of this invention to provide a sound-activated system which employs a motor for imparting a rotary movement to some object for a predetermined length of time.
It is another object of this invention to provide specific sound-activating circuitry for use with such systems.
These and other objects will become apparent from the following description and appended claims.